This invention relates to machining centres and guard for routers for for such a machine.
A machining centre usually comprises a work table on which a processing tool, for example, a router or milling cutter, moves along three Cartesian axes. The centre may be controlled by a computer, e.g. a personal computer, in which must be first installed a processing program. A vertical guide supports a first carriage which runs along the guide by means of a first motor. The tool is fixed to the first carriage. The vertical guide is supported by a second carriage, running by means of a second motor along a first horizontal guide which is supported at one end by a third carriage running by means of a third motor along a second horizontal guide. The second horizontal guide is arranged at a right angle to the first horizontal guide, and the support moves along the three Cartesian axes over the horizontal work table. The three motors are connected to the computer, which may be integrated in the machine and may comprise a microprocessor sending to the motors signals for movement by reading position and movement data from memories connected thereto.
In stationery machinery, such as the type to which the present invention relates, and where the tool is any milling tool, it maybe provided with guarding in order to protect operators from inadvertently contacting the tool bit and possibly injuring themselves.
Moreover, it is highly desirable to provide dust extraction facilities, so that the environment around the center can be kept clean and dust free. Hitherto, it has been the practice to surround the cutter of the tool with a depending curtain of brush, the interior of which is supplied with vacuum from a dust extraction device. Such an arrangement suffers a number of disadvantages, namely that the curtain shrouds the tool bit so that the cutter cannot be viewed by the operator, and secondly, at the maximum depth of cut, the brush is often so distorted by its contact with the workpiece that gaps appear which reduce the effectiveness of the extraction.
Consequently, it is an object of the present invention to provide a machining center which overcomes these disadvantages, or at least mitigates their effects. In accordance with this invention, there is provided a machining center comprising a tool mounted in a frame for movement along three Cartesian axes, in which the tool is a router comprising a body fixed to the frame and which body houses a motor driving a rotary tool bit depending from said body, at least one column being slidable with respect to said body along an axis parallel the rotation axis of said bit and mounting a router base having an aperture through which said tool is adapted to plunge to perform cutting operations, said base comprising a hood having openings towards said bit and leading to a dust extraction port for connection to a vacuum source.